“Pirfenidone treatment significantly decreased the Kyn/Trp ratio (0.030 ± … 0.025 ± 0.010 post-treatment, p = 0.048) whilst nintedanib treatment significantly increased blood GSH (486 ± 70 μmol/… μmol/L, p = 0.006) and reduced ADMA concentrations (0.501 ± 0.094 vs. ….071 μmol/L, p = 0.024).”